I'd modified them as Jeff described in the past, but having the repair boards saves significant time when doing a bunch. It also allows non-precision cuts, since it doesn't matter if you accidentally destroy the old connections down to the IC body. It also results in a repaired module with no battery-on-a-wire, but is still short enough to fit under SBus cards for the machines that have NVRAM under card slots. Since the repair boards come panelized in 2x5 grids, I can assemble 10 at a time, which again, when you're doing a heap of NVRAMs, saves a lot of time.
Thanks, Jonathan On Tue, Nov 27, 2018 at 4:05 PM Alan Perry via cctalk <[email protected]> wrote: > One reason that I buy the new NVRAMs is that I keep failing at modifying > them. Got the polarity wrong and fried one. I destroyed one cutting down > to the terminals. I got one working, but have had problems convincing > the battery to stay in place and not rip the leads off. There is a > reason I am a software, not a hardware, guy :) > > alan > > On 11/27/18 12:34 PM, Jeffrey S. Worley via cctalk wrote: > > When I bought that Sparcstation 4/330 at Computer Parts Barn, the 48T02 > > was one of the problems with it. The chip looks like a piggieback rom > > encapsulated in epoxy. > > > > I was not reinventing the wheel at the time, I think, because it was > > the year 2000 or so, but I looked for a replacement and found them hard > > to come by. So, knowing the battery was most likely the fault, I went > > about fixing that bit. > > > > The battery accounts for the high profile. You do not have to cut the > > entire doggone batter off, the terminals are at one side, iirc, the > > right-hand side if the notch is to your left. It is high on the epoxy, > > so all you need do is cut down an eighth of an inch in that region, > > just shave that top edge until you expose the battery terminals. I > > forget how I determined the polarity of them, perhaps I plugged it into > > the board after and tested the terminals for power, but all you do once > > you've exposed the terminals is solder a power and a ground wire to > > them and attach a 3volt battery. I used a pack with two AA's, in a > > case so they are user-replaceable. They are probably STILL keeping > > time in that machine, wherever DHS took it and my MEGA ST4 and DG > > MV4000/dc... That's another story. > > > > So refurbishing these chips is a cakewalk, takes 15 minutes (the second > > time 'round), and will work til' doomsday. > > > > Best regards, > > > > Jeff > > > >
